Refuse burner apparatus

ABSTRACT

A subterranean burning chamber for burning refuse, which is covered by a frusto-conical metal shell, comprises a steel structure that is refractory lined and has hollow walls that are fluid-cooled. Means is provided for maintaining the chamber in place when bouyant forces are present.

United States Patent to] Watts Oct. 21, 1975 REFUSE BURNER APPARATUS Y [56] References Cited [75] Inventor: Ralph E. Watts, Florence, SC. UNITED STATES PATENTS 3,354,847 l1/1967 Clement et al. 110/7 [73] Assgnee' gwpers pttsburgh 3,452,690 7/1969 Tarbox et al. 110/7 3,483,832 12/1969 Ballet al l10/7 [22] Filed: May 30, 1973 3,704,676 12/1972 Davies et al. 110/8 [21] P Primary Examiner-Kenneth W. Sprague [44] Published under the Trial Voluntary Protest f f' 8 0rFirm-Shermal1 H. Barber; Olin Program on January 28, 1 975 as document no. Williams; Oscar Brumback B 364,022.

Related US. Application Data 53 b Z f b f su erranean urnmg c am er or urnmg re use, [63] 'commuatmnm panof which is covered by a frusto-conical metal shell, comprises a steel structure that is refractory lined and 110/8 has hollow walls that are fluid-cooled. Means is pro- [58] Fieid 8 A 8 C vided for maintaining the chamber in place when i lo/is R bouyant forces are present.

7 Claims, 6 Drawing Figures U.S. Patent OCL 21, 1975 US. Patent Oct. 21, 1975 Sheet 2 of2 i /35\ car 57 /27 /5/ /99 i Z! M l I 1 my FIG. 3

' shown in FIG. 1; and

REFUSE BURNER APPARATUS CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 339,337, filed Mar..8, 1973, now U.S. Pat. No. 3,807,323.

BRIEF SUMMARY OF THE INVENTION A refuse burner, in accordance with the present invention, includes a subterranean, open-topped pit or chamber, that has hollow, fluid-cooled structural walls,

' the lower part of which. are encased in concrete. The

top of the pit or chamber is covered by a frusto-conical shell with means at the top for collecting effluent given off by burningmaterial in the pit or chamber. Such effluent is recirculated into the bottom of the pit or chamber.

For a further understanding of the invention and for features and advantages thereof, reference may be made to the following description and the drawing which illustrates a preferred embodiment of equipment in accordance with the invention which is suitable for practicing the method of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In. the drawings: FIG. 1 is a schematic vertical sectional view of apparatus in accordance with one embodiment of the present invention;

FIG. 2 is a plan view of the ratus of FIG. 1;

FIG. 3 is a view along line III--III,of FIG. 4; FIG. 4 is a view along line IV--IV of FIG. 3; FIG. 5 is a view of the top portion of the apparatus lower portion of the appa- FIG. 6 i s'a view along line VI-VI of FIG. 5.

DETAILED DESCRIPTION Referring to FIG. 1, a refuse. burner 111, in accordance with one embodiment of the present invention, comprises a frusto-conical shell 113 that surrounds and is located above a subterranean pit or burning chamber; is generally rectangular in shape; is open topped; and is substantially entirely subterranean except for a small portion at the top that-extends a short distance above ground level. Such pit or burning chamber 125 v is constructed in the manner shown generally in FIGS.

The frusto-conical shell 1 13 includes an angle iron or structural steel skeleton frame 115 that is covered, preferably, with aluminized sheet steel shell 117. The skeleton frame may, of course, be made of any other structural members as preferred. Both the frame 115 and the shell 117 are supported upon a circular concrete footing 119 disposed at ground level 121. The

The pit or burning chamber has four vertical side walls that are formed of outer 127 and inner 129 membranes, such as steel plating or heavy gauge sheet steel. These outer 127 and inner 129 membranes are maintained in spaced-apart parallel relation by a plurality of vertically arranged structural beams, such as H-beams 131. Each of the I-I-beams 131 is provided with a plurality of holes 133 in its web for apurpose that will be explained hereinafter.

The outer plating or membrane 127 is supported by vertically spaced-apart, horizontally arranged Lbeams 135 and by short intercostal sections of vertically arranged structural angles 137. The wall membranes or plating 127, 129'and the H-beams 131 are capped by a horizontal cap plate 139, and they are supported upon a steel base plate 141. Thus, the wall structure is hollow and fluid-tight, and the holes 133 provide a passageway through the structural H-beams 131 for the flow of a fluid, which may be air, in the wall structure to cool it. Adjacent the bottom of the hollow wall structure on the right hand side (FIG.-1) is an upwardly inclined baffle plate 134, that does not contact, but is spaced apart from the inner plating 129; thereby providing a passage for fluid within the hollow wall space 199 emerging I from cross-over pipes 201, mentioned hereafter.

The inner surface of the inner membrane or plating 129 is covered with an insulating material 143 that may be mineral wool or any other suitable insulating material. Contiguous with the insulating material 143 is a lining of refractory bricks 145. 1

The bottom of the burning pit or chamber 125 is loose granular material, such as a layer of sand 147, disposed over the bottom plating 141. In the sand layer 147 there are a plurality of cross-over pipes or conduits 201 that afford fluid communication between the spaces 199 in the hollow wall structure.

Extending through the layer of sand 147, are a plurality of grate boxes 149 which are fitted with top grate structures 150; each grate box 149 is connected to a riser 151, extending through the bottom plating 141 and sand 147, connected to a conduit 153 below the bottom of the pit or burning chamber 125.

The top or cap plate 139 is perforated by a plurality of vents 211 which are covered by adjustable damper plates 213 so as to regulate the amount of air leaving the hollow wall space 199 during firing of the burner pit 125. The vents 211, as will be noticed from FIG. 2, are located in only one longitudinal cap plate, but they are located in both end cap plates.

The lower one third portion of the wall structure and the bottom of the pit of burning chamber 125 are encased in concrete 155. The concrete 155 acts to prevent the hollow, bouyant wall structure of the pit or burning chamber 125 from moving upwardly whenever sub-surface water is present in sufficient quantity to exert a bouyant force on the chamber 125. Anchor bolts 157 connect the side walls to the concrete, as shown. Of course, other means than concrete may be used, if preferred, to provide enough extra weight in the structure to counteract bouyancy effects of subsurface water and the likeon the chamber 125. Further, in regions where sub-surface bouyancy is not a consideration, the concrete 155 may be omitted, but yet, in most instances, it may be installed to provide a more rigid support for the pit or burning chamber 125.

Associatedwith the pit or burning chamber 125 is a fly ash reinjection system and a fluid-cooling system for the wall structure of the chamber 125.

The fly ash reinjection system includes a collector cone 159, shown in- FIG. 5, that is located just below the'cylindrical-shaped tubular member 123 at the top of the frusto-conical shell 113.

The collector cone 159, however, has a conical-outer shell 161 that merges with a conduit 163 at its top, the conduit 163 being disposed horizontally, as shown, through the shell 113, and directed downwardly outside the shell, as suggested. The collector cone 159 has a bottom portion 165, shown -in FIG. 6, that is comprised of a structural grid 167 made up of angles 169 to which are applied concentric annular plates 171, so arranged that there are annular spaces 173 between adjacent concentric annular plates; a center plate 175 is provided that is not annular in shape.

Conduit 163 connects with a centrifugal type fan 177, that is provided with suitable motor drive 179, sit- 'uated on a concrete slab or base 181 adjacent the pit or burning chamber 125, as suggested in FIG. 2. A discharge conduit 183 from the fan 177 connects to the "header conduit 153 (FIG. 1) with which the risers 151 and grate boxes 149 are associated, as mentioned previously.

On the foundation or concrete slab 181, there is another fan 185, preferably of the centrifugal type, having a suitable motor drive 187, that receives ambient air through an intake 189 and that discharges the air under pressure into conduit 193. Conduit 193 carries the air 7 either into a plenum chamber 191 or, when a damper 19 4 is properly set, into conduit 196 that connects to conduit 198 within the hollow wall structure, about where shown in FIG. 1. The conduit 198 has a plurality of slotted holes 200 in its periphery, along its length,

that allow air to enter the hollow wall space 199. The

air passes downwardly in the hollow wall space 199 on the' right-hand side as viewed in FIG. 1, through the cross-over pipes 201 into the end wall spaces via pipes 201a, and thence upwardly in the hollow wall spaces to exit vents 211 and outlet conduit 195, as shown schematically by the flow arrows. The conduit 195 may pass through the hollow shell 113 and terminate outside thereof if preferred.

Associated with the plenum 191 and wall structure are a'plurality of nozzles 197 that extend slightly into the pit or burning chamber 125 and at a downward angle, about as shown in FIG. 1. I

In operation, a quantity of wood and paper are placed on the floor of the pit or burning chamber, and they are ignited in a suitable conventional manner. A damper 46 at the top of the shell 113 is closed initially and the fly ash reinjection system is activated to circulate the effluent arising from the burning wood and paper. The effluent is recirculated back into the chamber and, thereby, does not escape to pollute the atmosphere.

The apparatus is quickly brought up to a working temperature as additional waste wood products and 1 maintains the walls of the pit or chamber relatively cool, and during the burning process, waste wood and other combustible material are introduced, more or less continually, into the chamber through the chute. In some instances a vehicle carrying such combustible material, may be admitted to the shell, through an opening therein, not shown) in order to dump its load into the chamber.

From time to time, or whenever it is deemed necessary or desirable, mobile equipment, such as a backhoe or other similar apparatus, may be admitted to the shell through the opening for the purpose of removing ash residue from the chamber. Such apparatus can easily approach close enough to the edge of the chamber to quickly and effectively remove the ash residue.

Those skilled in the art will recognize that when the walls of the chamber have reached a desired temperature, the fan, which'connects to the nozzles within the chamber, is operated. Air jetting from such nozzles creates a curtain over the burning material and, together with the fly ash recirculating system, develops very high temperatures within the chamber. The temperature, about 2,000F, is well above that generally regarded as desirable, which is around 800F, to obtain complete and effective burning of waste material and the effluent produced.

From the foregoing description of one embodiment of the invention, those skilled in the art should recognize many important features and advantages of it, among which the following are particularly significant:

Very high combustion temperatures, as high as about 2,000F, are obtained in the combustion zone of the chamber of the apparatus of the invention. Since a temperature of only about 800F will produce clean burning of waste wood products, it is readily apparent that, at the high temperature achieved in the apparatus of the invention, no smoke or effluent escapes to the atmosphere; 1

Because the temperature in the subterranean chamber may be as high as 2,000F, the refractory-lined walls, with insulating space in which fluid such as air under pressure circulates, can better withstand such a high temperature that the thin shell portion above ground; I

Because the distance between the combustion zone in the chamber and the collection cone in the present apparatus is greater than that of burner apparatus known from the prior art, the fly ash cools down somewhat, and the upward, thermally generated velocity of the fly ash in the present apparatus is much lower than that developed in prior art burner apparatus. These advantages result in less wearing of the conduits of the present fly ash reinjection system;

That batch feeding of waste wood products and other consumable material into the chamber is readily afforded, since there is a large access door and opening in the shell of the apparatus;

That ash removal from the chamber can also be readily accomplished, since mobile ash removal equipment is easily moved'into and out of the shell through the access door and opening;

Since almost the entire burning chamber is below ground level, a uniform temperature profile down the walls of the chamber is effected, and no thermal shocks are set up from water or wind, and the like, or from any water seepage below ground level.

Flooding of the burning chamber is prevented, since it is protected by the above-ground shell;

The structural characteristics of the burning chamber, particularly the fluid-cooled walls and the sand floor, promote long life in service with very little loss in burning time or expense; and

The sand floor in the chamber absorbs high-impact loads from batch feeding of large items such as pole cut-offs, stumps, scrap wood, and the like; the sand floor also is an effective insulating medium to prevent spalling of the concrete base.

Although the invention has been described herein with a certain degree of particularity, it is understood that the present disclosure has been made only as an example, and that the scope of the invention is defined by what is hereinafter claimed.

What is claimed is:

1. In a refuse burner apparatus including a hollow wall structure of inner and outer spaced-apart plates and a layer of insulating material disposed on said inner wall plate, with a layer of refractory material covering the insulating layer; with a cap plate covering the top of the wall structure; and with a bottom plate on which the wall structure rests, the combination with said wall structure of:

a. a first conduit communicating with said hollow wall structure for introducing a cooling fluid thereinto to cool said wall structure;

b. means for introducing a cooling fluid into said first conduit;

c. means for flowing said cooling fluid out of said wall structure;

d. a second conduit carrying said cooling fluid; and

e. a third conduit communicating with said second conduit and having a plurality of nozzles that direct fluid flowing in said third conduit into said burner apparatus.

2. The invention of claim 1 including:

a. damper means for regulating the flow of fluid in said conduits.

3. In a refuse burner apparatus including a hollow wall structure formed by spaced-apart membranes with a cap plate covering the top of said wall structure and a bottom plate on which the wall structure rests, the combination with said wall structure of:

a. means for carrying cooling fluid into one portion of said hollow wall structure; and

b. conduit means for carrying said cooling fluid from said one portion to another portion of said hollow wall structure;

4. The invention of claim 3 including:

a. means surrounding and coacting with a portion of said wall structure for resisting upward forces acting on said wall structure.

5. The invention of claim 3 including:

a. a first conduit carrying a cooling fluid into the space between said membranes;

b. a second conduit having a plurality of nozzles that direct fluid flowing therein into said burner apparatus; and

c. damper means for regulating the flow of fluid in said first and second conduits.

6. The invention of claim 3 including:

a. a baffle in said another wall structure portion that is spaced apart from one membrane of said hollow wall structure; and

b. adjustable vent openings in said hollow wall structure whereby said cooling fluid may escape therefrom.

7. In a refuse burner apparatus, the improvement comprising:

a. a hollow wall structure comprised of inner and outer membranes with means therebetween for maintaining said membranes in spaced-apart relation;

b. means for introducing a cooling fluid into one portion of said hollow wall structure; and

0. means for conveying said fluid from said one wall structure portion to another wall structure portion. 

1. In a refuse burner apparatus including a hollow wall structure of inner and outer spaced-apart plates and a layer of insulating material disposed on said inner wall plate, with a layer of refractory material covering the insulating layer; with a cap plate covering the top of the wall structure; and with a bottom plate on which the wall structure rests, the combination with said wall structure of: a. a first conduit communicating with said hollow wall structure for introducing a cooling fluid thereinto to cool said wall structure; b. means for introducing a cooling fluid into said first conduit; c. means for flowing said cooling fluid out of said wall structure; d. a second conduit carrying said cooling fluid; and e. a third conduit communicating with said second conduit and having a plurality of nozzles that direct fluid flowing in said third conduit into said burner apparatus.
 2. The invention of claim 1 including: a. damper means for regulating the flow of fluid in said conduits.
 3. In a refuse burner apparatus including a hollow wall structure formed by spaced-apart membranes with a cap plate covering the top of said wall structure and a bottom plate on which the wall structure rests, the combination with said wall structure of: a. means for carrying cooling fluid into one portion of said hollow wall structure; and b. conduit means for carrying said cooling fluid from said one portion to another portion of said hollow wall structure.
 4. The invention of claim 3 including: a. means surrounding and coacting with a portion of said wall structure for resisting upward forces acting on said wall structure.
 5. The invention of claim 3 including: a. a first conduit carrying a cooling fluid into the space between said membranes; b. a second conduit having a plurality of nozzles that direct fluid flowing therein into said burner apparatus; and c. damper means for regulating the flow of fluid in said first and second conduits.
 6. The invention of claim 3 including: a. a baffle in said another wall structure portion that is spaced apart from one membrane of said hollow wall structure; and b. adjustable vent openings in said hollow wall structure whereby said cooling fluid may escape therefrom.
 7. In a refuse burner apparatus, the improvement comprising: a. a hollow wall structure comprised of inner and outer membranes with means therebetween for maintaining said membranes in spaced-apart relation; b. means for introducing a cooling fluid into one portion of said hollow wall structure; and c. means for conveying said fluid from said one wall structure portion to another wall structure portion. 